Rancilio Silvia Overheat

So yesterday, I did something stupid and left the apartment with my Silvia on. Not only was it on (which I've done before) but I left the steam switch on, which meant that the boiler was full of steam and prone to overheating. Luckily this guy saved me and explained exactly how to fix it, but the only reason I saw it was because he described it as the "Silvia won't heat problem". Perfect. Exactly my search query.

http://www.terrystockdale.com/coffee/resetting_silvia.php